Rivet assembly apparatus



Jan. 23, 1968 A. E. DI MAlO 3,364,553

RIVET ASSEMBLY APPARATUS Filed Oct. 21 1965 3 Sheets-Sheet 1 INVENTOR. 1 M 9 ALMA:

ATTORNEYS lcngmauwOflw Jan. 23, 1968 A. E. DI MAlO ,3

RIVET ASSEMBLY APPARATUS 3 Sheets-Sheet 2 Filed Oct. 21, 1965 INVENTOR.

FIG. 3

ATTORNEYS Jan. 23, 1968 A. E. DI MAIO 3,364,553

RIVET ASSEMBLY APPARATUS Filed Oct. 21. 1965 I 5 Sheets-Sheet 5 H WHIIH will UH U FEED DRIVE L REST RETRACT FIGS 8 a. 3mm hamwaiad ATTORNEYS v United States Patent 3,364,553 RIVET ASSEMBLY APPARATUS Anthony E. Di Main, Georgetown, Mass., assignor to Marson Fastener Corporation, Chelsea, Mass, a corporation of Massachusetts Filed Oct. 21, 1965. Ser. No. 499,828 4 Claims. (Cl. 29-211) This invention relates to tubular rivet assemblies and, more particularly, to apparatus for the assembly of a fastener characterized by: an external tubular rivet having a deformable forward end and a flanged rearward end; and an internal mandril locked to the forward end and projecting through the rearward end to permit withdrawal of the mandril and deformation of the forward end of the rivet with the aid of a hand rivet-setting tool.

The primary object of this invention is to provide a novel apparatus for the automatic assembly of such rivets and such mandrils. The apparatus provides for feeding a continuous sequence of rivets and a continuous sequence of mandrils through separate tracks to seats in a rotating turret where each of the sequence of mandrils is automatically inserted into each of the sequence of rivets, and resulting sequence of assemblies is progressively moved through a series of positions in which they sequentially assume their final form. The foregoing apparatus is characterized by: reliable repetitive assembly of rivets and mandrils without distortion of parts, with consequent maintenance of uniform quality; positive timing via continuous rotation of the turret, in order to eliminate both harmful vibration and undesired time delay, of the types common in prior intermittent motion apparatus; and simplified automatic operation resulting from a single drive mechanism and unidirectional rotation.

Other objects of the present invention will in part be obvious, and will in part appear hereinafter.

This invention accordingly comprises the apparatus possessing the construction, combination of elements and arrangement of parts which are exemplified in the following detailed disclosure, the scope of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the present invention, reference should be had to the following detailed description taken in connection with the accompanying drawings, wherein;

FIG. 1 is a partly cross sectional view of a typical rivet and mandril assembly, which may be fabricated by an apparatus of the present invention;

FIG. 2 is a fragmentary, perspective view of a preferred apparatus for fabricating assemblies of the type shown in FIG. 1;

FIG. 3 is a wedged, cross-sectional view of the apparatus of FIG. 2, taken substantially along the line 33;

FIG. 4 is a cross-sectional view of the apparatus of FIG. 2, illustrating a component thereof, the cross-section being taken substantially along the line 4-4; and

FIG. 5 is a diagrammatic view showing comparative positions of the punches, as if they were aligned in a fiat plane rather than about an arc.

FIG. 1(a) is a cross-sectional view of a typical rivet assembly of an outer rivet 14 and an inner mandril 10, produced by the apparatus of this invention. Each mandril has a head portion 12, engaging the forward end of rivet 14. Rivet 14 has a forward constricted end engaging a crimped portion of mandril 10 at and a rearward flanged end spaced therefrom. In use, after the rivet has been inserted through the aligned openings of a pair of workpieces as shown in FIG. 1(b), a tensile force pulling the rearward end of mandril 10 tends to deform the forward end of rivet 14 to form a forward flange and the rearwardly extending part of the mandril separates from the remainder thereof to leave the work pieces in locked con- 3,354,553 Patented Jan. 23, 1968 dition. The apparatus illustrated in FIGS. 2 to 5 comprises: a pair of chutes 30, 34 for providing a continuous sequence of mandrils and rivets respectively; a mandril wheel 26 for seating a sequence of mandrils at its periphery; a rivet wheel 28 for seating a sequence of rivets at its periphery; and a plurality of punches to be described below for driving the mandrils into the rivets as the wheels rotate.

FIG. 2 omits for clarity a top support plate 21, which is shown in FIG. 3. Extending through a cylindrical turret 18 is a series of twenty-four elongated reciprocable punches 20, supported in a circular array, adjacent punches being arcuately spaced fifteen degrees apart. Three vertical elongated posts 22, at the apices of a theoretical triangle, support a stationary internal cylindrical cam 24, by which the positions'of punches 20 are controlled. Between mandril wheel 26 and rivet wheel 28, referred to above, is a jaw wheel 27 which cooperates with punches 20 to assemble the mandrils and rivets. Turret 18, mandril wheel 26, jaw wheel 27 and rivet wheel 28 are fixed to each other as by bolts 29. Mandril wheel 26, rivet wheel 28, and jaw wheel 27 are each apertured at equally spaced intervals around their respective peripheries in substantially the same positions radically and angularly as are the punches in the turret to provide registered seats for continuous sequences of rivetsand mandrils. Aforementioned chute 30 is. a channel-shaped track, adjacent to mandril wheel 26, which allows mandrils at 32 to be fed, one at a time, into the seats at the periphery of mandril wheel 26. Aforementioned chute 34 is a channel-shaped track, adjacent to rivet wheel 28, which allows rivets at 36 to be fed, one at a time, into the seats at the periphery of rivet wheel 28.

A base 38 is fixed to top plate 21 by posts 22. A downwardly depending shaft 52, which is fixed to top plate 21 as at 53 rotably mounts turret 1S, mandril wheel 26, jaw wheel 27 and rivet wheel 28. Rotation is effected by a drive shaft 46, which is keyed to rivet wheel 28. As a cycle begins, first punches Ztl sequentially are driven into their bottoming positions or uppermost positions and the seats of mandril wheel 26 and of rivet wheel 28 are rotated into their mandril and rivet receiving positions. As the cycle continues next the mandrils and rivets are driven into assembled condition by the punches which are constrained by cam 24 in a manner to be described below. As the cycle ends, finally the finished rivet assemblies are released and the punches then retract.

As shown in FIG. 3, the mandril and rivet loading stations are adjacent to one another. Rigidly attached to each punch 20 is a roller bearing 42 that runs in an endless groove 44, which is presented by the aforementioned cam 24. Groove 44 varies in height throughout its circular extent, thus lowering the punches into their mandril driving positions and elevating the punches into their loading positions with each rotation of the turret. Drive shaft 46 is driven via a clutch, by a geared motor which powers the entire apparatus.

Each mandril 32 at its loading station drops into a seat in mandril wheel 26 under gravity and aided by a vacuum at an inlet 47. Each rivet 36 at its loading station drops into a seat in rivet wheel 28 under gravity and aided by a vacuum at an inlet 49. As the mandrils are seated, they individually centered with respect to corresponding rivets by die apertures 48 at the periphery of jaw wheel 27. As shown in FIG. 4, each die aperture 48 is provided by a jaw 51 that is slightly slidable in a notch 53 in jaw wheel 27. Each jaw has a tongue and each notch has a groove, by which the jaws are retained by the jaw wheel. Each jaw is pressed into an outwardly limited position by a spring 51 Jaws 51 are not rigidly attached to jaw wheel 27 in order to allow springs 50 to align the die holes with the mandril and rivet seats in the event that the mandril should enter at a slight angle. A groove 54 around the top surface of base 38 allows clearance for the depth required to drive the mandrils into the rivets. Adjustment of cam 24 for the proper setting of the depth traveled by punches 20 is provided by a series of set screws 56, which bear against post 22. Vacuum is established at inlets 47, 49 through a conduit at the center of shaft 52.

In operation of the illustrated apparatus, reference now is made to FIGS. 4 and 5, wherein rivet wheel 28, rotating in a clockwise direction, is shown divided into four segments. From the starting point of tract 30, there is a feed in time associated with a 60 arc of rotation, a drive time associated with a 120 arc of rotation, a rest time associated with a 60 arc of rotation and a retract time associated with a 120 arc of rotation. At the end of any cycle, mandril 10 and rivet 14 are assembled and drop into a chute 40, for packaging.

Since certain changes may be made in the above apparatus without departing from the scope of the object herein involved, it is intended that all matter disclosed herein, or shown in the accompanying drawings be interpreted in an illustrative and not a limiting sense.

What is claimed is:

1. Apparatus for manufacturing tubular rivet assemblies of the type including an outer tubular rivet portion and an inner mandril portion, said tubular rivet portion having a forward deformable extremity and a rearward flange and said mandril having a forward head in contact with said deformable portion and a rearward extension projecting through from tubular portion, said apparatus comprising a mandril Wheel having seats at its outer periphery for the reception of a succession of said mandril portions, a rivet wheel having seats at its outer periphery for the reception of a succession of rivet portions, a turret having a sequence of guides at its periphery and a sequence of punches reciprocably constrained within said guides, said rivet Wheel, said mandril wheel and said turret being connected for rotation together with said guides of said turret, said seats of said mandril wheel and said seats of said rivet wheel being in registration, a stationary base on which said rotation occurs, and a cam fixed with respect to said stationary base, said punches having followers in association with said cam, whereby they are reciprocated in said guides as said rotation occurs in order to drive successive mandril portions of said sequence into successive rivet portions of said sequence.

2. The apparatus of claim 1 wherein a jaw wheel is interposed between said mandril wheel and said rivet wheel, said jaw wheel providing a sequence of die openings in registration with said sequence of seats of said mandril wheel and with said sequence of seats of said rivet Wheel, said sequence of punches cooperating with said sequence of die openings in order to precisely position said sequence of mandril portions with respect to said sequence of rivet portions during assembly thereof.

3. The apparatus of claim 1 wherein said cam provides an internal cam channel, of which increments are spaced at a sequence of positions that are relatively close to and relatively remote from said mandril wheel and said rivet wheel, each of said punches having a follower roller in association with said channel whereby the longitudinal position of each of said punches is determined by its relation with said cam.

4. The apparatus of claim 1 wherein there are provided a feed channel for a sequence of mandril portions to said seats of said mandril wheel and a feed channel for a se quence of rivet portions to said seats of said rivet wheel.

References Cited UNITED STATES PATENTS 2,768,763 10/1956 Meilstrup 292l1 2,810,249 10/1957 Wysocki 29-208 3,299,495 1/1967 Nysocki 29208 THOMAS H. EAGER, Primary Examiner. 

1. APPARATUS FOR MANUFACTURING TUBULAR RIVET ASSEMBLIES OF THE TYPE INCLUDING AN OUTER TUBULAR RIVETS PORTION AND AN INNER MANDRIL PORTION, SAID TUBULAR RIVET PORTION HAVING A FORWARD DEFORMABLE EXTREMITY AND A REARWARD FLANGE AND SAID MANDRIL HAVING A FORWARD HEAD IN CONTACT WITH SAID DEFORMABLE PORTION AND A REARWARD EXTENSION PROJECTING THROUGH FROM TUBULAR PORTION, SAID APPARATUS COMPRISING A MANDRIL WHEEL HAVING SEATS AT ITS OUTER PERIPHERY FOR THE RECEPTION OF A SUCCESSION OF SAID MANDRIL PORTIONS, A RIVET WHEEL HAVING SEATS AT ITS OUTER PERIPHERY FOR THE RECEPTION OF A SUCCESSION OF RIVET PORTIONS, A TURRET HAVING A SEQUENCE OF GUIDES AT ITS PERIPHERY AND A SEQUENCE OF PUNCHES RECIPROCABLY CONSTRAINED WITHIN SAID GUIDES, SAID RIVET WHEEL, SAID MANDRIL WHEEL AND SAID TURRET BEING CONNECTED FOR ROTATION TOGETHER WITH SAID GUIDES OF SAID TURRET, SAID SEATS OF SAID MANDRIL WHEEL AND SAID SEATS OF SAID RIVET WHEEL BEING IN REGISTRATION, A STATIONARY BASE ON WHICH SAID ROTATION OCCURS, AND A CAM FIXED WITH RESPECT TO SAID STATIONARY BASE, SAID PUNCHES HAVING FOLLOWERS IN ASSOCIATION WITH SAID CAM, WHEREBY THEY ARE RECIPROCATED IN SAID GUIDES AS SAID ROTATION OCCURS IN ORDER TO DRIVE SUCCESSIVE MANDRIL PORTIONS OF SAID SEQUENCE INTO SUCCESSIVE RIVET PORTIONS OF SAID SEQUENCE. 